Manufacture of artificial products of viscose



1933- H. PFANNENSTIEL ET AL 1,933,999

MANUFACTURE OF ARTIFICIAL PRODUCTS OF VISCOSE Filed Dec. 27, 1929 Patented' Nov. 7, 1933 MANUFACTURE OF ARTIFICIAL PRODUCTS OF VISCQSE Hugo Pfannenstiel and Harry Meyer, Dessau in Anhalt, Germany, assignors to I. G. Farbenindustrie Aktiengesellschaft, Frankfort-on-the-r Main, Germany Application December 27, 1929, Serial No. 416,985, and in Germany December 29, 1928 Claims.

ucts, for instance artificial silk, horsehair, bands or other artificial textile products are guided on their way between the spinning nozzle andthe collecting device over rubbing surfaces,. such as rods, rolls, rollers or helical or otherwise shaped surfaces in such amanner that a tension is produced in the thread, the said surfaces being heated to a raised temperature. This stretching device may be manufactured of any suitable material, as for instance, of glass or any acid-proof metal. The temperature to which .thestretching device is heated generally is higher than that at which the spinning process is carried out and maybe raised up to about 100 C. The stretchingdevice may be heated in any suitable manner,

for instance electrically or, when choosing hollow stretching means, by introducing a hotgas or liquid or steam. The stretching device may be a stat'onary one or it may comprise rotating rollers which revolve according to the special require-- ments with the sameor with a different speed .as the collecting device.

When operating with such rotatable heated rollers, the heat is sup plied preferably through the axis.

in order to reduce the crystall'zation of salts from the liquid adhering to the products drawn out of the spinning bath, the hot stretching device may be irrigated in any suitable manner. As an irrigating liquid preferably water is used, however, other treating liquids such as alkalies, acids, salt solutions, may be applied, the temperature of the said irrigating lquor being kept at that of the stretching device.

The new stretching process described above is superior over those hitherto known on the following reasons.

In the case of strong extension, for instance, the threads may be stretched according to the invention without difiiculties, whereas with a similar device with unheated rollers the performance of the spinning process is either impossible or can only be carried out with repeated breakage of the threads. A further advantage of stretching the threads. over heated surfacesresides in concentrating, if desired, the coagulating liquid adhering the artificial product while it slides over tion the heated surfacesand thus enhancing its action. The qual ty of the resulting products is improved by reduction of breakage of the capillary threads and by increasing simultaneously the tensile strength of the fiber.

The following examples illustrate the inven- Example 1.In a usual process ofspinning artificial silk from a viscose solution, the freshly coagulated threads leaving the precipitating bath, are guided over a stationary hollow roller of glass or an acid proof metal having a diameter of about 4 centimeters and'being provided with an axial supply and discharge piping by which it is heated with steam .of almost 100 C. Then the threads are collected on a bobbin. The number of breakages of the capillary threads is re- NITIED STATESU'PA-TENT" OFFICE i duced with respect to an ordinary stretching' process to a third to a fourth. The tensile strength of the silk is increased to 10 to 20 per cent.

Example 2.-The roller for stretching the fibers as used in Example 1 is arranged in such a manner that it rotates round the supply and discharge piping and is heated by water of about 80 to 90 C. The peripheral velocity of the stretching roller is 10 per cent less than that of the collecting bobbin. A similar good result is obtained.

In the accompanying drawing, a spinning device according to the invention is shown by way of a sketch.

Fig. 1 isa front view and Fig. 2 a side view. In thetwo figures, the same. parts are designated by the same references. a is a spinning noz- Zle arranged in 'a spinning trough g. The threads IL leaving the precipitating bath are guided on their way'from the spinning nozzle 0!. to the collecting device 0 over a stationary roller 12 provided with an inlet d and a discharge piping e for the steam. f is a thread guide.

Obviously, a heated stretching device according to the invention may be used in combination with other means known in' the art of manufacturing artificial viscose products, without departing from the scope of the present invention. What we claim is:- 1. In the manufacture of artificialmaterials of viscose thestep which comprises stretching the material on its way from the spinning nozzle to the collecting device by guiding it over a rubbing surface which is heated to a temperature higher than the temperature at which the other spinning operations are performed.

2. In the manufacture oi. artificial materials of viscose the step which comprises stretching the material on its way from the spinning nozzle to the collecting device by guiding it over a rubbing surface which is heated to a temperature dipping into the precipitating bath, a collecting device for winding up the threads produced, a stretching device between said nozzle and said collecting device and means to heat said stretching device.

5. In a machine for manufacturing artificial materials from a viscose solution in combination a trough containing a precipitating bath for viscose, a pipe for supplying viscose, a spinning nozzle fixed to said pipe, said spinning nozzle dipping into the precipitating bath, a collecting device for winding up the threads produced, a stretching device between said nozzle and. said collecting device and means to heat said stretching device to a temperature of from about 50 to about 100 C.

HUGO PFANNENS'IIEL. HARRY MEYER. 

